Jeez, I love Leo and Don so much, wow. The heavily movie inspired heads are doing god's work here for me. And I like the crap glued onto these 2, too, fitting the characters so well. Not sure about Shredder yet, though.
There's a Pixel Dan walkthrough where Peter from Mondo explains to Dan that they're approaching these as if the 90s movies happened and Shredder returned again, but this time having met Krang with the resources of Dimension X, etc. Basically the movies but in the toon context, so with tech based in the 90s, that sort of thing.